diff options
Diffstat (limited to 'target/linux/lantiq')
| -rw-r--r-- | target/linux/lantiq/patches-4.9/0093-spi-double-time-out-tolerance.patch | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/target/linux/lantiq/patches-4.9/0093-spi-double-time-out-tolerance.patch b/target/linux/lantiq/patches-4.9/0093-spi-double-time-out-tolerance.patch new file mode 100644 index 0000000000..68b0ffe570 --- /dev/null +++ b/target/linux/lantiq/patches-4.9/0093-spi-double-time-out-tolerance.patch @@ -0,0 +1,37 @@ +From 833bfade96561216aa2129516a5926a0326860a2 Mon Sep 17 00:00:00 2001 +From: Hauke Mehrtens <hauke@hauke-m.de> +Date: Mon, 17 Apr 2017 01:38:05 +0200 +Subject: spi: double time out tolerance + +The generic SPI code calculates how long the issued transfer would take +and adds 100ms in addition to the timeout as tolerance. On my 500 MHz +Lantiq Mips SoC I am getting timeouts from the SPI like this when the +system boots up: + +m25p80 spi32766.4: SPI transfer timed out +blk_update_request: I/O error, dev mtdblock3, sector 2 +SQUASHFS error: squashfs_read_data failed to read block 0x6e + +After increasing the tolerance for the timeout to 200ms I haven't seen +these SPI transfer time outs any more. +The Lantiq SPI driver in use here has an extra work queue in between, +which gets triggered when the controller send the last word and the +hardware FIFOs used for reading and writing are only 8 words long. + +Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> +Signed-off-by: Mark Brown <broonie@kernel.org> +--- + drivers/spi/spi.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/spi/spi.c ++++ b/drivers/spi/spi.c +@@ -1004,7 +1004,7 @@ static int spi_transfer_one_message(stru + ret = 0; + ms = 8LL * 1000LL * xfer->len; + do_div(ms, xfer->speed_hz); +- ms += ms + 100; /* some tolerance */ ++ ms += ms + 200; /* some tolerance */ + + if (ms > UINT_MAX) + ms = UINT_MAX; |